Which cranial nerve has primarily sensory function and no motor component?

• A. Trochlear
• B. Trigeminal
• C. Vestibulocochlear
• D. Facial

Answer: (C)

This question hinges on identifying a cranial nerve that is mainly sensory and does not innervate muscles. The vestibulocochlear nerve carries the senses of hearing and balance from the inner ear to the brain, and it has no intrinsic motor function to skeletal muscles. In other words, it transmits sensory information rather than controlling movements. By contrast, the trochlear nerve acts as a motor nerve to the superior oblique eye muscle; the trigeminal nerve has both sensory input to the face and motor output to muscles of mastication; the facial nerve provides motor signals for facial expression as well as sensory taste. So, the vestibulocochlear nerve is the best fit because it serves purely sensory roles for hearing and balance.